Our overall objective is to develop an inhaled, safe and efficacious Rho kinase (ROCK) inhibitor as novel maintenance therapy for patients with chronic obstructive pulmonary disease (COPD), with the unique potential to slow disease progression. COPD is one of the leading causes of morbidity and mortality worldwide due to high disease prevalence and ineffective therapies. COPD is the 3rd leading cause of death in the United States and is responsible for billions of dollars in annual healthcare costs. Current treatments are largely palliative and have minimal impact on the key inflammatory processes in COPD that inexorably lead to disease progression and associated decline in lung function. Therefore, there is an urgent need to develop drugs that target components of COPD not affected by present medicines. There is increasing evidence that the ROCK isoforms, ROCK1 and ROCK2, play an important role in the maintenance of airways tone and in lung inflammation and remodeling, suggesting that ROCK inhibitors may represent a novel approach for COPD. Theratrophix (TRX) has identified potent inhibitors of the human ROCK1 and ROCK2 isoenzymes, including the lead TRX-101, that are more potent than the prototype ROCK inhibitors, fasudil and Y-27632. The results of the previous Phase 1 SBIR (1R43HL104902-01) demonstrated that TRX-101 had bronchoprotective, anti-inflammatory and anti-fibrotic effects in rodent systems in vitro and in vivo. In this proposal we outline a series of decision-making preclinical studies to evaluate and progress an inhaled ROCK inhibitor, TRX-101 or analog, to the preclinical development phase as a potential novel therapeutic for COPD; the profiling is underpinned by investigation in several disease-relevant systems. The specific aims of this Phase 2 proposal are: Aim 1: Developability profile of TRX-101 and analogs, including pharmacokinetic (PK) characteristics - to determine which compound has the desired characteristics for a long-acting, inhaled compound, including sustained lung retention and pharmacodynamic activity, and the physicochemical characteristics for inhaled delivery; Aim 2: Assessment of bronchodilator and anti-inflammatory effects of selected TRX-compound in human lung systems - A series of key translational medicine studies will be conducted using human precision-cut lung slices and human airway smooth muscle cells, and human lung fibroblasts; Aim 3: Evaluation of inhaled TRX- compound in mouse models of cigarette smoke-induced COPD, to determine the in vivo effects in a disease-relevant animal model that is resistant to corticosteroids. By achieving the specific aims outlined it is anticipated that Theratrophix will have identified a quality inhaled ROCK inhibitor which will be ready to enter IND-enabling studies as a critical step towards initiation of clinical trials in COPD. Based upon the ability to produce potent bronchodilation, anti-inflammatory activity and an impact on tissue remodeling in a single molecular entity, an inhaled ROCK inhibitor has the potential to have a unique profile which could offer unprecedented therapeutic benefits in COPD, in particular slowing disease progression.